Chapter 12 - Cloud Classification

Question 1

What does WMO stand for

Answer 1

World Meteorological Organisation

Question 2

x3 Cloud shapes and their development

Answer 2

Cumulative - vertical development
Stratiform - horizontal development
Cirrus - Ice crystals/ fine filaments

Question 3

x3 Cloud levels with heights

Answer 3

Low - surface- 6500 ft
Middle - 6500 - 23,000 ft
High 16500 - 45000 ft

Question 4

Which cloud classification do you get in low, middle and high

Answer 4

Low = Strato (Water droplets) 
Middle = Alto (mixture of ice crystals and water droplets)
High = Cirro (Ice crystals)

Question 5

Why is it dangerous flying in clouds with super cool ice droplets? what temperature is it at it’s worse

Answer 5

0 - -10. Cloud just above freezing level. no nuclei for the ice to join - a/c will ice rapidly if flown through

Question 6

How many Okta in
SKC
FEW
SCT
BKN
OVC

Answer 6

0
1-2
3-5
5-7
8

SFSBO

Question 7

What is a METAR

Answer 7

Actual weather at the time at that place

Question 8

What is a TAF

Answer 8

A Forecast

Question 9

How do we measure cloud base?

Answer 9

Ceilometer

Question 10

How Oktas is considered Cloud ceiling and %

Answer 10

Over 50% = 5 oktas/ BKN

Question 11

Lowest cloud base =

Answer 11

Where ever the lowest reading is in the TAF/METAR

Question 12

x3 High Clouds

Answer 12

Cirrus (Ci)
Cirrostratus (Cs)
Cirrocumulus (Cc)

Question 13

x2 Middle Clouds

Answer 13

Altostratos (As)

Altocumulus (Ac)

Question 14

x3 Low Clouds

Answer 14

Stratus (St)
Stratocumulus (Sc)
Nimbostratus (Ns)

Question 15

What do we associate with Nimbo

Answer 15

Precipitation

Question 16

Describe a Cirrus

Answer 16

Delicate filament, white, patchy

Question 17

Describe a Cirrostratus

Answer 17

Transparent, whitish cloud with a veil-like or smooth appearance. gives halo effect

Question 18

Describe a cirrocumulus

Answer 18

Thin, white, patchy cloud. grainy mackerel like skin.

Question 19

Describe a Altostratus

Answer 19

Greyish / blueish cloud sheet or cloud layer

Question 20

Describe a Altocumulus

Answer 20

White / Grey and form sheet/ layers of cloud. Larger rounded masses.

Question 21

Describe a Nimbostratus

Answer 21

Grey/ dark cloud layer. blot out the sun - low and ragged

Steady precipitation

Question 22

Describe a Stratus

Answer 22

Grey, layered cloud with a uniform base

Question 23

Describe a Stratocumulus

Answer 23

Round masses, rolls. white sheet or patchy type - always has dark layers

Question 24

Describe a Cumulus

Answer 24

Detached clouds which is dense with sharp outline

Question 25

Describe Cumulusnumbus

Answer 25

Heavy dense cloud with huge vertical extent

Question 26

Description of clouds for cumulus x5

HMCCC

Answer 26

Humilis - low level, fairweather below 10,000
Mediocris - low level, medium vertical extent, max 10,000
Congestus - greater vertical extent up to 25000
Calvus - vertical up to 45,000, sharp lines
Capillatus - ice crystals at top give hair like appearance

Question 27

Fractus goes with

Answer 27

Broken appearance with St or Cu

Question 28

Castellanus looks like

Answer 28

Acc castle like appearance

Question 29

Mammatus goes with

Answer 29

Cu, udder like

Question 30

Lenticularis goes with

Answer 30

Cc, Ac, Sc and has a Lens shape

Question 31

For turbulence what is the difference between moderate and severe

Answer 31

moderate a/c in control

severe a/c can be out of control